Officials from NOAA, the National Oceanic
and Atmospheric Administration, announced new elevations for the state
of Louisiana to improve the accuracy of the state’s survey benchmarks
and insuring they will remain accurate for longer periods than in
the past. The announcements were made during a presentation at the
Coastal Zone ’05 conference, the largest international conference
for coastal resource management professionals.

“Using
the new technologies available to us such as Global Positioning System
and NOAA’s Continuously Operating Reference Stations will allow
us to provide accurate elevation reference points in an efficient
and timely manner,” said Richard
Spinrad, Ph.D., assistant administrator for NOAA’s National
Ocean Service. “Planners will be better able to determine road
and bridge heights relative to water and ground levels from these
data, thus assuring evacuation routes and shipping lanes have appropriate
clearance to avoid flooding and obstructions.”

Currently NOAA’s National Geodetic
Survey is analyzing the historical leveling data as well as new leveling
and GPS surveys. They are feeding the data into updated scientific
models in order to provide more accurate elevations on a number of
benchmarks in southern Louisiana.

NOAA has enjoyed the support and cooperation
of a number of institutions and organizations in the Gulf Coast region,
especially the Harris/Galveston Coastal Subsidence District, in coordinating
efforts to detect and measure subsidence. Many of the specifications
and procedures used, and projected for use in the Louisiana Coastal
region, were developed in conjunction with the HGCSD.

The Louisiana Spatial Reference Center
was established in 2002 at Louisiana State University in response
to users’ and public safety needs. The LSRC operates in conjunction
with NOAA to develop and provide height modernization procedures in
Louisiana as well as to share technology development with others.
Congress has specifically provided height modernization funding in
fiscal year 2005 for the Gulf Coast states of Alabama, Mississippi,
Louisiana and Texas.

“These new heights are considerably
more accurate than what we have been able to measure previously,”
said Charlie Challstrom, director of NOAA’s National Geodetic
Survey. “There is much work to be done - including providing
tools, and educating users on how to utilize the new information for
future projects.”

NOAA officials noted it is critical that
users of the elevation data apply it in accordance with new approaches
being developed, and work with the Louisiana Spatial Reference Center
to improve the geospatial reference system in Louisiana. While there
will be fewer specific benchmarks maintained, the overall accuracy
of the heights will be maintained for longer periods.

NOAA officials emphasized that NOAA does
not predict the rates of subsidence nor attempt to determine its causes
in Louisiana or elsewhere. NOAA is the supplier of data that are then
used by the U.S. Geological Survey, U.S. Army Corps of Engineers,
state agencies, academics, emergency planners, engineers, surveyors,
environmental restoration efforts, and others to determine those rates
based on various models.

NOAA released “Technical Report
50” this spring, a compilation of rates of subsidence between
1920 and 1995. The vertical rates in the report, according to the
National Geodetic Survey, may not reflect current or future rates
of subsidence.

Recently completed GPS surveys through
December, 2004 are being added to NOAA’s database and will validate
a framework of benchmarks that can be confirmed for use in accurate
surveys.

The National Oceanic and Atmospheric
Administration, an agency of the U.S. Department of Commerce, is dedicated
to enhancing economic security and national safety through the prediction
and research of weather and climate-related events and providing environmental
stewardship of our nation’s coastal and marine resources. Through
the emerging Global Earth Observation System of Systems (GEOSS), NOAA
is working with our federal partners and nearly 60 countries to develop
a global Earth observation network that is as integrated as the planet
it observes, predicts and protects.